P1179: EFFECTIVENESS OF CENTRAL NERVOUS SYSTEM PROPHYLAXIS STRATEGIES IN DIFFUSE LARGE B-CELL LYMPHOMA
Authors: F. Z. Eraslan, T. Toptas, T. Tuglular, I. Atagunduz
Journal: HemaSphere (2022)

Background: Central nervous system recurrence is seen in 5% of patients diagnosed with DLBCL. CNS relapse is associated with survival limited to months. Therefore, determining the patients who are at high risk of CNS relapse and selecting the most efficient prophylactic approach is one of the mainstays of treatment. IV-MTX and IT-MTX are widely used in CNS prophylaxis. Nevertheless, the efficiency of IV-MTX and IT-MTX in preventing CNS relapse was not proven in large study groups or in prospective studies. Aims: Our study aims to verify the efficiency of current CNS prophylaxis in preventing CNS relapse in DLBCL patients. Additionally, association of CNS relapse with survival and the correlation of CNS-IPI score, age, albumin, origin of cell, and DHL/DEL status with cumulative CNS relapse incidence. Methods: The data from 190 patients were analyzed retrospectively. Among the 89 patients who had been classified as high-risk group for CNS relapse, seven were administered IT-MTX, 17 received IV-MTX, and remaining 65 patients received no prophylaxis. Results: Median age was 57(18-88) and male to female ratio was almost equal (male: 48.8%). At the time of diagnosis, 66.8% of the patients were defined to have advanced stage disease. All of the cohort included 89 patients (46.8%) who were at high risk for CNS relapse. Cumulative CNS relapse risk at one-year was estimated as 12.2%, 9.5%, 4.5% for patients received IV-MTX, IT-MTX and no prophylactic treatment, respectively. Two-year cumulative CNS relapse risk was 24.5%, 12.2%, 6.0% for patients who received IV-MTX, IT-MTX and no prophylaxis, respectively (p=0.008). The frequency of DEL or DHL were higher in patients who received IV-MTX (41.1%). CNS relapse rate was 25% and 50% for patients who did not receive prophylaxis and who did, respectively. In patients with DEL, CNS relapse rate (33.3%) did not differ for those who received prophylaxis and those who did not. In our study, we found overall CNS relapse incidence 6.8% in DLBCL. Median time to CNS relapse was 12 months in all cohort. Median overall survival after occurrence of CNS relapse was two (95% CI: 0-4.9) months. We found that the patients who had high CNS-IPI score were at six times greater risk of CNS relapse than those with low and intermediate CNS-IPI score (9.0% and 1.5% after 12 months, 11.6% and 2% after 24 months) (p=0.03). Despite the univariate analyses revealed a statistically significant association, multivariate analysis has shown that albumin level is not an independent predictor for CNS relapse. Additionally, we have shown that CNS-IPI score, DHL/DEL status are strong predictors of CNS relapse in DLBCL patients. Image:Summary/Conclusion: Independent predictors of CNS relapse in DLBCL are DHL/DEL status and CNS-IPI score. No predictive relationship was proven to exist between CNS relapse and gender, albumin levels, cell of origin classification by Hans-algorithm. Patients with CNS relapse had poor prognosis (median survival two months). IV-MTX prophylaxis has been shown to have no preventive effect on CNS relapse in high risk DLBCL population. Due to this data, significant changes in prophylactic approach against CNS relapse in high risk DLBCL patients is required.